The proposed research will continue investigations on: Alterations in the metabolic pool at the site of both aqueous humor and cerebrospinal fluid production in groups of unoperated animals and in animals in which bilateral superior cervical sympathetic ganglionectomy will be performed. In addition, a third group of sham-operated animals will be used. In this latter group surgery will proceed only to the point where the carotid arteries and cervical sympathetic ganglia are exposed. That supersensitivity to catecholamines takes place in sympathectomized animals has been shown previously in this and other laboratories. Ocular fluid dynamics in all animals will be determined by repeated weekly testiing of ocular pressure (IOP) (with the Mackay- Marg tonometer), as well as measurement of pupil size. A base-line of measurements will have been made for a period of about two weeks prior to the performance of any surgery. Again, prior to surgery, this base-line will be followed by a period of testing of ocular responses to phenoxybenzamine (PBA), norepinephrine (NE) and prostaglandins (PGs). At the termination of a study, the animals will be anesthetized, the eyes cannulated and outflow resistance and IOP measured. The animals will then be sacrificed and tissues and fluids removed. The metabolism and/or concentrations of cyclic adenylic acid (cyclic-AMP) and PGs will be of particular interest. We shall, in other words, look closely at the metabolic and physiological nature of ocular and non-ocular tissues in animals which would be made catecholamine-supersensitive (via the above surgical procedure) at sites of sympathetic innervation as compared with sham-operated and unoperated animals. Alterations in tissue metabolism will be examined, also.